The Countryside Alliance is predicting this Sunday's Liberty and Livelihood march in London will be the biggest British civil rights demonstration in living memory.

They expect the parade of at least 250,000 people to bring large parts of central London to a standstill for up to six hours.

We're not expecting any of the difficulties we sometimes have with demonstrations in central London

Andy Trotter Met deputy assistant commissioner

Police have prepared a huge operation to co-ordinate the safe movement of such huge crowds, although a relatively small number of extra officers will be on duty.

They are advising protesters and anyone planning to visit London on the day to leave their cars at home - and an appeal has also been issued for marchers not to bring pets, farm machinery or livestock.

Neither the police nor organisers are anticipating trouble from Countryside Alliance (CA) opponents or more radical pro-hunting groups.

	:	March Route
Liberty and Livelihood March

The march - postponed by the foot-and-mouth outbreak last year - is billed by the CA as a protest over the proposed ban on hunting with dogs and what they say are other threats to rural values, customs and livelihoods.

Participants will be entertained by static bands and five huge video screens en route and marshalled by at least 1,600 stewards - the same number of extra police on duty.

More expected

The CA's chief march organiser, James Stanford, said he be would happy if numbers equalled the 250,000 who turned out for a similar event in London in 1998.

But with registered marchers already numbering 210,000 and many more expected to turn up on the day, they believed the actual tally would be much higher, he added.

"Without doubt it will be the largest civil rights demonstration in London in recent memory, certainly for 150 years," Mr Stanford told reporters at Scotland Yard on Thursday.

However an anti-hunting campaign group said the numbers of people expected to attend the march had been falling steadily since March.

Mike Hobday of the League Against Cruel Sports said: "Whatever the eventual numbers, the majority of the public believe that there can be no liberty to be cruel to wild animals."

Metropolitan Police Deputy Assistant Commissioner Andy Trotter said: "This will be a huge policing operation in terms of the scale of road closures and the numbers of people but the [policing] needs are far, far lower than for any other march of this sort and scale because of the nature of the marchers, the co-operation of the Countryside Alliance and the number of stewards they will have on duty."

Trouble not expected

Mr Trotter said his officers' task would mainly be a "people moving operation".

"We're not expecting any of the difficulties we sometimes have with demonstrations in central London," he said.

They were aware of only one counter-demonstration, thought to be being planned by anti-capitalist group Class War, and there may well be others but violence was not anticipated.

"We're expecting a peaceful day but obviously we've got contingencies for anything else that might happen."

Mr Hobday said that instead of staging a counter demonstration, the League Against Cruel Sports was urging its supporters to "go out and enjoy this one-off cruelty free day in the countryside".

"It will be a good day for foxes, and for deer and a good day to enjoy the countryside," he said.

Splinter group 'threat'

Echoing Mr Trotter, Mr Stanford said they were determined it would be a "peaceful and well disciplined operation".

He said he had no information the so-called Real Countryside Alliance - a splinter group blamed most recently for defacing two of England's most famous hillside white horses with huntsmen - were planning to disrupt Sunday's events.

"The Real Countryside Alliance have nothing to do with us," he insisted. "They are a group of people with rather anarchic tendencies."

Earlier on Thursday at Downing Street the CA staged its curtain raiser to the march with rural workers including a rat catcher, a blacksmith and huntsmen leaving a 6ft by 5ft "calling card" spelling out Sunday's mission statement for Tony Blair.

Sunday's marchers will start from two different places: Hyde Park Corner, codenamed 'Liberty'; and Blackfriars, codenamed 'Livelihood'.

March routes

Two sets of marchers start separately, converge and then split again 'Liberty' starts Hyde Park Corner, then Piccadilly, St James's, Pall Mall and Cockspur St 'Livelihood' starts Blackfriars, then Victoria Embankment Routes converge in Whitehall 'Liberty' disperses from Victoria Street 'Livelihood' disperses from Westminster Bridge

They will follow different routes to converge and walk in symbolic silence down Whitehall, before splitting again from Parliament Square to disperse separately nearby.

Mr Stanford said they now regretted the codenamed routes because some sections of the media had portrayed it as a split between "toffs and plebs" when they were both "absolutely identical".

"The reason we are having two marches is because we do not wish to disrupt London for longer than we can avoid."

In fact, police are advising people to avoid central London altogether if possible this weekend.

Car drivers are being particularly warned as the road closures for Sunday's march coincide with others marking European Car Free Day.